Andrea Markowski, warden of the Edmonton Institution for Women, provided the inquest with the overview ahead of the jurors' visit to the prison in which Ashley Smith choked to death more than five years ago.
The panel heard that inmates can only be placed in segregation if there is "no reasonable alternative."
Keeping prisoners isolated is usually done because they pose an "undue risk" to staff or other inmates or to themselves, Markowski testified.
Segregated inmates are allowed out of their cell for at least an hour a day of fresh air, she said, but can be out longer for showers or to use the telephone.
Periodic reviews are required by law to see if segregation remains warranted, said Markowski, who never had any dealings with Smith.
The goal is always to facilitate reintegration in the general population at the "earliest possible date," she said.
Asked by one lawyer whether prolonged segregation makes reintegration more difficult, Markowski said: "It's possible but it depends."
Smith, 19, of Moncton, N.B., spent much of her life behind bars in isolation — at times at her own request. She died at the Grand Valley Institution in Kitchener, Ont. — one of Canada's five federal prisons for women — in October 2007.
Court heard how segregation triggers regular reviews, including getting an opinion from a psychiatrist or psychologist every 30 days on whether an inmate can withstand ongoing isolation.
However, court heard the review clock would restart with a transfer, a policy that changed after Smith's death.
Still, Julian Falconer, the Smith's family lawyer, said nothing had changed in the oversight structure when it comes to segregation.
"Ashley Smith was shunted from isolation cell to isolation cell," Falconer said to Markowski.
"The correctional investigator subsequently found that her administrative segregation was not in compliance with the law."
Markowski said she was not familiar with details of the Smith case.
The presiding coroner, Dr. John Carlisle, said he wants the impact of prolonged segregation on Smith's mental health explored.
Coroner's court also heard how policy bars the transfer of suicidal or self-harming inmates to another prison unless a psychologist deems it useful to minimize the potential for self-injury or suicide.
Smith was moved from prison to prison across the country, even though she increasingly engaged in self-harming behaviour. She frequently hid ligatures in her body cavities.
"Under the law, a body cavity search could take place by a medical practitioner, if the woman consented," Markowski said.
"I've never authorized a body cavity search. I've always found a way to work it out."
On Monday, at the first day of hearings, the five-women jury heard how Smith choked while guards at Grand Valley, ordered not to intervene, looked on.
Jurors will get a first-hand look at the facility on Thursday.
Markowski said segregated inmates usually wear prison-issued tracksuits, while general population prisoners have the choice to wear regular clothes.
"On Thursday, we won't see women walking around in orange jumpsuits?" asked Jocelyn Speyer, coroner's counsel.
"No, we will not," Markowski said.
As of last October, about 575 women were in federal custody and more than 13,000 men, court heard.
The inquest continues Wednesday with a witness expected to offer a psychiatry overview.